I'm having a hard time setting up the network in our house. It has three levels (basement, ground floor, first level).

The WLAN is set up by an ASUS RT-N12 router which provides perfect coverage for the ground floor and the basement. However, I set up my "home office" in the basement where the signal barely arrived.

So I purchased a TP-Link TL-WA901ND (300 Mbps) Access Point which I set up in the other corner of the ground floor to expand the ASUS router's range. I used the AP's Repeater mode for that. The distance between my computer and the TP-Link AP is 6-7 meters. There is a staircase going down from the ground floor to the basement so there are no solid walls between the computer and the AP.

This setup mostly works (I am writing this from the basement) but it is not reliable (the signal strength sometimes goes down to ~40% of the max) sometimes so I wonder if I am doing it correctly or if there is a better way.

Screenshot of the router's and the AP's dashboard screen follow:

Any comments on what I am doing wrong or hints for improvement are appreciated.

Thank you.

UPDATE

Tried one more thing, setting up the TP-LINK AP in Access Point mode. That way, I can make it use a different SSID. I enabled WDS/Bridge so that it expands the range of the ASUS router (see screenshot). That does not work, either, if I connect to the network set up by the TP-LINK device (PELSTER-2), I can't reach the external network (the Internet). It seems the problem always comes back to this, the TP-LINK does not have access to the external network, whatever its mode of operation.